[PATCH 5.17 0515/1126] livepatch: Fix build failure on 32 bits processors

Greg Kroah-Hartman
2022-04-05T08:21:07Z

From: Christophe Leroy <christophe.leroy@csgroup.eu>

[ Upstream commit 2f293651eca3eacaeb56747dede31edace7329d2 ]

Trying to build livepatch on powerpc/32 results in:

kernel/livepatch/core.c: In function 'klp_resolve_symbols':
kernel/livepatch/core.c:221:23: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
221 | sym = (Elf64_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info);
| ^
kernel/livepatch/core.c:221:21: error: assignment to 'Elf32_Sym *' {aka 'struct elf32_sym *'} from incompatible pointer type 'Elf64_Sym *' {aka 'struct elf64_sym *'} [-Werror=incompatible-pointer-types]
221 | sym = (Elf64_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info);
| ^
kernel/livepatch/core.c: In function 'klp_apply_section_relocs':
kernel/livepatch/core.c:312:35: error: passing argument 1 of 'klp_resolve_symbols' from incompatible pointer type [-Werror=incompatible-pointer-types]
312 | ret = klp_resolve_symbols(sechdrs, strtab, symndx, sec, sec_objname);
| ^~~~~~~
| |
| Elf32_Shdr * {aka struct elf32_shdr *}
kernel/livepatch/core.c:193:44: note: expected 'Elf64_Shdr *' {aka 'struct elf64_shdr *'} but argument is of type 'Elf32_Shdr *' {aka 'struct elf32_shdr *'}
193 | static int klp_resolve_symbols(Elf64_Shdr *sechdrs, const char *strtab,
| ~~~~~~~~~~~~^~~~~~~

Fix it by using the right types instead of forcing 64 bits types.

Fixes: 7c8e2bdd5f0d ("livepatch: Apply vmlinux-specific KLP relocations early")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Petr Mladek <pmladek@suse.com>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5288e11b018a762ea3351cc8fb2d4f15093a4457.1640017960.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/livepatch/core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 585494ec464f..bc475e62279d 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -190,7 +190,7 @@ static int klp_find_object_symbol(const char *objname, const char *name,
return -EINVAL;
}

-static int klp_resolve_symbols(Elf64_Shdr *sechdrs, const char *strtab,
+static int klp_resolve_symbols(Elf_Shdr *sechdrs, const char *strtab,
unsigned int symndx, Elf_Shdr *relasec,
const char *sec_objname)
{
@@ -218,7 +218,7 @@ static int klp_resolve_symbols(Elf64_Shdr *sechdrs, const char *strtab,
relas = (Elf_Rela *) relasec->sh_addr;
/* For each rela in this klp relocation section */
for (i = 0; i < relasec->sh_size / sizeof(Elf_Rela); i++) {
- sym = (Elf64_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info);
+ sym = (Elf_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info);
if (sym->st_shndx != SHN_LIVEPATCH) {
pr_err("symbol %s is not marked as a livepatch symbol\n",
strtab + sym->st_name);
--
2.34.1